[Help Thread] Petrus Discussion and Help thread

[Noahaha]

The algorithms listed on the "Step 4b tricks" are by no means a definitive list; there are many more cases for each corner position. It seems with that page that Lars is trying to display some tricks for specific cases and not trying to cover every possible case.

If this is the case you are describing

these are both optimal solutions
U' R U2 R' U2 R U' R'
U' R U2 R' U' R U2 R'

Thankyou very much!

I do believe though that this is the only case missing for step 4b, as it is the only one I have ever come across that was not covered by that page.

 

[pi.cubed]

Also, I'm a little confused about your examples because none of them seem to be for step 4b of Petrus (The positions they solve do not have the BR, BRD and DR pieces solved).

Oh yeah you're right. Sorry about that. The first one should be right but for the second two the first R' should just be an R.
So now it's the same as Brest said.
It's good your question has been answered with no mistakes now.
I should have used VisualCube like Brest did actually.

 

[Noahaha]

Oh yeah you're right. Sorry about that. The first one should be right but for the second two the first R' should just be an R.
So now it's the same as Brest said.
It's good your question has been answered with no mistakes now.
I should have used VisualCube like Brest did actually.

I'm very glad for all the help. I feel like I'm doing something wrong though by not doing 4b intuitively. It might not all matter anyway because I'm considering learning EJLS. Any thoughts?

 

[immortalchaos29]

I'm very glad for all the help. I feel like I'm doing something wrong though by not doing 4b intuitively. It might not all matter anyway because I'm considering learning EJLS. Any thoughts?

I first learned on Petrus as well. And when I did 4b I did it the same way. My observation was that the majority of the algorithms ARE intuitive algorithms, anyway. I view them as two steps (or three if the are combined, but misoriented.)

1)separate the pair (if needed).
2)join the pair with proper orientation.
3)insert the joined pair in the slot.

Seen this way I really didn't feel guilty about memorizing them, since it wasn't like memorizing letters on a page like what 1LPLL was. Some of the algorithms are not so intuitive however, (seeing as how they temporarily break the block) and those are especially worth memorizing.

Just my thoughts...

 

[Cubenovice]

I'm more so planning to learn this method for fewest moves than speed though, so would I then just use the full Petrus method or the little changes that I described?

For fewest moves you typically use neither one of them

Two typical FMC starts:
Blockbuilding up to 2x2x3
EO
"Full Petrus" ends here
F2L minus last slot
Manipulate Edges and corners to leave 3,4 or 5 corners
Solve corners by commutators (preferably as insertions into earlier parts of the solution)

OR
Blockbuilding up to 2x2x3
"Full Petrus" ends here
Blockbuilding to F2L minus last slot
EO
Manipulate Edges and corners to leave 3,4 or 5 corners
Solve corners by commutators (preferably as insertions into earlier parts of the solution)

I call this "typical" starts because in FMC anything goes: some of the best results have been done CFOP-ish with skips
But in general:
- blockbuilding is the way to go
- stay away from OLL and PLL (unless you can use a short OLL to skip PLL or leave some corners to be inserted)

Read:
- the FMC thread
- AVG's writeup on FMC tricks and tips
- weekly comp for examples

 

[Noahaha]

Is EJF2L worth learning? Using exclusively? Using in certain cases?

 

[immortalchaos29]

Is EJF2L worth learning? Using exclusively? Using in certain cases?

I don't know if I am the most qualified to answer this because I haven't taken the time to learn it fully mysef. From what I have seen I've noticed it has some real potential in the following ways:

1) one really cool property is that you can often use a really short solution for a step 1 and 2 combination if the corner orientation is ignored and fixed later with the LL.
2) could help with recognition
3) algorithms are easy and fast
4) rare FMC cases
5) certain BLD cases

and some drawbacks

1) memorizing of algs -_-
2) adds an AUF to the solve before LL - with lots of practice I don't know if this would amount to much but at first it could be hard.
3) think you will be using a few more turns on average.

My conclusion is that it certainly couldn't hurt to learn. I say try it for a while and see if it seems to fit your style better. Might as well

 

[Noahaha]

I don't know if I am the most qualified to answer this because I haven't taken the time to learn it fully mysef. From what I have seen I've noticed it has some real potential in the following ways:

1) one really cool property is that you can often use a really short solution for a step 1 and 2 combination if the corner orientation is ignored and fixed later with the LL.
2) could help with recognition
3) algorithms are easy and fast
4) rare FMC cases
5) certain BLD cases

and some drawbacks

1) memorizing of algs -_-
2) adds an AUF to the solve before LL - with lots of practice I don't know if this would amount to much but at first it could be hard.
3) think you will be using a few more turns on average.

My conclusion is that it certainly couldn't hurt to learn. I say try it for a while and see if it seems to fit your style better. Might as well

I'll definitely learn it, and at the very least use it in difficult 4b cases like when the corner and edge are already together but twisted.

 

[5BLD]

Is EJF2L worth learning? Using exclusively? Using in certain cases?

It's useful, and there are only a few, 16 iirc cases. Go ahead if you have the patience to learn them, they are useful when you get annoying 2 gen last pair cases and it's nice to be able to just solve the corner unoriented.

Also why not check out WV?

 

[mariano.aquino]

First of all, i'm so happy this thread came back to life!
now, something funny:
i learnt coll, and then i realized i could use it as a non-optimal CLL for 2x2x2. Before that i had learnt ejf2l, and then i realized i could use it for a non-optimal Guimond approach as well!
So, after learning it, grab your favourite 222 and have some fun!

PS: you can check my site for some algs lists and links =)

 

[oll+phase+sync]

Is EJF2L worth learning? Using exclusively? Using in certain cases?

For me the biggest problem was, to recognize an good EJF2L oportunity durig step 2 ,knowing a CE pair is a pair becomes a new difficulty (the corner must be attached to the correct side of the edge)

my plan was: doing step 2 EJF2L exclisive for a while, to train my recognition skill. but for unknown reason never really did.

 

[Noahaha]

Is it worth paying attention to what edges are flipped while putting in the last edge of the 2x2x3 block? I feel like even if you find that the two edges that get flipped can't be bad edges, it will still improve look ahead. Does anyone use this regularly?

 

[5BLD]

I do that regularly... I find any 'predictions' useful definitely for look-ahead.

 

[Noahaha]

I do that regularly... I find any 'predictions' useful definitely for look-ahead.

Thanks. My lookahead is generally pretty good between steps 2 and 3, so this shouldn't be too hard to integrate. I've also found that it helps to know whether the edge you are displacing is going to be flipped or not, since it ends up in the perfect position for an R U R' or an L' U' L.

 

[immortalchaos29]

You may already be doing this but I took a lesson from my CFOP practice and found it to be monumentally important for Petrus as well.

Similar to building the cross on the bottom, you will want to build the 2x2x2 block on one of the D positions (I prefer one on the BD but this is less important.) Just like in any other method, practice solving using as few cube rotations as possible. Doing this will help not only your lookahead but also your execution. In fact, I've found it easier to minimize grip changes in Petrus than in CFOP.

 

[Noahaha]

You may already be doing this but I took a lesson from my CFOP practice and found it to be monumentally important for Petrus as well.

Similar to building the cross on the bottom, you will want to build the 2x2x2 block on one of the D positions (I prefer one on the BD but this is less important.) Just like in any other method, practice solving using as few cube rotations as possible. Doing this will help not only your lookahead but also your execution. In fact, I've found it easier to minimize grip changes in Petrus than in CFOP.

At the end of my 2x2x3 it is at the bottom left, so while I am placing the last edge of it I put it in the back for EO, but you might be right that it would be easier to solve it in the back to begin with since I like to do EO head on.

EDIT: If you watch this video: http://www.youtube.com/watch?v=yQJa8iHA5Ww

You'll notice that pandaman uses a regrip before EO, but I think the important thing is that he looked ahead so that he wasn't disoriented due to the grip change and could start making moves right away.

 

[JLarsen]

Is EJF2L worth learning? Using exclusively? Using in certain cases?

Honestly it's not worth it IMO. I used to use it semi-frequently and it got me some really good singles every now and then but overall it didn't really improve my times. However, IT'S FREAKIN COOL.

Also - can we please phase out the term EJF2L? The amount of work put into creating this "method" is not nearly enough to steal the title away from it's rightful owner - Lucas Garron. It's just using the I and IM subsets of MGLS in a Petrus solve.

 

[pi.cubed]

Honestly it's not worth it IMO. I used to use it semi-frequently and it got me some really good singles every now and then but overall it didn't really improve my times. However, IT'S FREAKIN COOL.

Also - can we please phase out the term EJF2L? The amount of work put into creating this "method" is not nearly enough to steal the title away from it's rightful owner - Lucas Garron. It's just using the I and IM subsets of MGLS in a Petrus solve.

What could be an alternative name for EJF2L?
And I would have thought that, considering that the incorrectly oriented corner can come from the 2x2x2, 2x2x3 or step 4, 'EJF2L' could be used on most solves. Because you could just make the 2x2x2 block ignoring the corner orientation every solve couldn't you?

edit: Oh wait do you mean that even when you used it it didn't improve your times?

 

[JLarsen]

What could be an alternative name for EJF2L?
And I would have thought that, considering that the incorrectly oriented corner can come from the 2x2x2, 2x2x3 or step 4, 'EJF2L' could be used on most solves. Because you could just make the 2x2x2 block ignoring the corner orientation every solve couldn't you?

edit: Oh wait do you mean that even when you used it it didn't improve your times?

The alternative name for EJF2L is the original - MGLS. That's what it is. Just a little trick. And yea, didn't improve my times. I used it for like a year in about 1/3 of my solves. Some of the cases are just....ugh

 

[JLarsen]

I copied this from here so more people would see it and I could get more feedback.
I've got a bad edges video tutorial on the way.

Just an update on this guide - I made some changes to wording, added some examples to cover 4 flips and 6 flips.

I've got a video tutorial on the way and I was looking for some guidance. I wanted to keep it brief but I find myself wondering at what point a brief tutorial just becomes rushed and way too fast. How long do you think the video should be? How many examples should I give? Did you like the format of this guide where I give scrambles and have the audience follow along? Should I do a lot of editing? I tried to make this guide sort of conversational instead of overly formal sounding. Did you like that?

I'm trying to make the end all be all bad edges tutorial so I want it to be really polished. That way later on down the road when I'm like 25 and looking back on my videos I don't hastily delete it out of embarrassment. I have a habit of doing that. Input appreciated!​

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